A hardware/software toolkit will be created to will allow personal computers to be used as accurately calibrated and controlled vision test instruments. This toolkit is predicated on the fact that modern PCs and displays (either CRT-based or flat screen) have sufficient computing power, resolution, and stability to function as reliable measurement tools. A major advantage of PC use for vision testing is that measurement software can be equipped with a high level of fault tolerance. Automated test routines including criterion-free and forced-choice procedures, catch trials, Bayesian threshold approximation, and other sophisticated psychophysical techniques can greatly alleviate the need for highly-trained technicians, and the operator's main task can be to make sure that the test subject is cooperative. This fault tolerance does not automatically extend to the setup and calibration of hardware, however. Screen intensity and chromaticity, test distance, room illumination, and a number of other variables can have a significant effect on test thresholds, even when testing the same subject on the same PC under similar conditions. We propose to develop a set of simple hardware tools and control software that will allow necessary hardware calibrations and setup to be performed quickly, reliably, reproducibly, and with a very modest level of training on the part of the operator. Under this phase I application we designed a prototype toolkit with hardware based on off-the-shelf components and software with a relatively primitive user interface. Under the subsequent phase II application we will develop a fully integrated hardware prototype, a fault-tolerant software package with a user-friendly interface, and a detailed product development and commercialization plan. A hardware/software toolkit will be created to will allow personal computers to be used as accurately calibrated and controlled vision test instruments. This toolkit is predicated on the fact that modern PCs and displays (either CRT-based or flat screen) have sufficient computing power, resolution, and stability to function as reliable measurement tools. [unreadable] [unreadable] [unreadable]